The present invention relates to a connecting blade for connecting two electrical connectors, a method of producing the connecting blade, and an electrical connector having the connecting blade.
Patent Reference 1 has disclosed a conventional connecting blade that connects two electrical connectors. In order to achieve high-speed signal transmission and noise reduction, a paired differential line is found to be effective, in which two transmission lines is paired. In the conventional connecting blade disclosed in Patent Reference 1, when a plurality of paired differential lines is formed on the conventional connecting blade, the paired differential lines may be formed of a straight pair and a cross pair arranged alternately, so as to reduce crosstalk between adjacent paired differential lines. In this case, it is necessary to improve electrical characteristics through reducing a signal transmission time lag (a skew) between the straight pair and the cross pair. For this reason, in the conventional connecting blade disclosed in Patent Reference 1, in order to reduce the skew, the straight pair is provided with a wave-shaped section over a substantially entire length thereof, so that the straight pair is formed to have a line length same as that of the cross pair.
However, when elements (lines) that compose the straight pairs and the cross pairs are formed through punching a sheet metal, it is difficult to use a common die for the straight pairs and the cross pairs even partially. For this reason, it is necessary to prepare special dies respectively for the straight pairs and the cross pairs, which have different shapes over the whole lengths thereof. Furthermore, in order to form the straight pairs with the wave-shaped sections, it is necessary to prepare a punching die having a complicated wave shape.
Patent Reference 2 has disclosed a conventional connecting blade having a different configuration. In the conventional connecting blade disclosed in Patent Reference 2, the cross pair has a parallel region, where the lines of the cross pair are parallel to each other except a crossing region of the cross pair. Further, the straight pair has a quasi-crossing region, which has a shape the same as that of the crossing region of the cross pair viewed from a direction perpendicular to a plate surface of an insulation board. The straight pair also has a parallel region, where the lines of the straight pair are parallel to each other except the quasi-crossing region of the straight pair. Accordingly, the straight pair has the same line length as that of the cross pair.
In the conventional connecting blade disclosed in Patent Reference 2, the quasi-crossing region of the straight pair is defined as a region corresponding to the crossing region of the cross pair other than the parallel region. In the quasi-crossing region, two lines of the straight pair are arranged not to cross, or are arranged close enough but not to cross but to look like as if the two lines cross as compared with the parallel region, when viewed in the direction perpendicular to the plate surface of the insulation board.    Patent Reference 1; U.S. Patent Application Publication No. 2010/0184307    Patent Reference 2; Japanese Patent Application Publication No. 2013-080648
As described above, the conventional connecting blade disclosed in Patent Reference 2 is configured so as to solve the problems of the conventional connecting blade disclosed in Patent Reference 1. However, the straight pair is provided with the quasi-crossing region, which is supposed to be straight. Accordingly, the straight pair tends to have a complicated shape, thereby increasing a cost of a die thereof. Furthermore, when even a slight change is made in a shape or a dimension of the quasi-crossing region of the straight pair, the change may affect the whole shape of the straight pair and the punching die. Accordingly, after the shape of the straight pair is finalized, if it is found to be difficult to completely eliminate the signal transmission time lag, it is difficult to change the whole shape of the die.
In view of the above-described problems, an object of the present invention is to provide a connecting blade capable of easily reducing the skew between a straight pair and a cross pair thereof, while the straight pair maintains a straight shape without being formed in a complicated shape such as a quasi-crossing region. Further, another object of the present invention is to provide a method of producing the connecting blade. A further object of the present invention is to provide an electrical connector having the connecting blade.
In the present invention, when it is found to be difficult to eliminate the signal transmission time lag after a shape of the cross pair is finalized, it is necessary to change only a part of a molding die for molding integrally with an insulating board thereof without changing the punching die. As a result, it is possible to provide the connecting blade, which is easily adjustable in comparison with a change required in the conventional technique, the producing method of producing the connecting blade, and the electrical connector having the connecting blade.